After police sent out stills from the video over the weekend, two people called police identifying the shooter as 35-year-old Seth Martin, according to court documents obtained by New Times.

The surveillance footage from the store showed the shooter, allegedly Martin, enter the store near 19th Avenue and Deer Valley Road, get a soda from the fountain, and walk to the cash registers, where he pulled a handgun on employee John Still.

Still, 46, is seen on the video attempting to knock away the gun before getting shot. According to court documents, Still apparently tried to open the cash register but was shot several more times.

Police say Martin grabbed his soda and headed for the door, turning back to shoot Still one more time before driving away in his truck.

After being identified by two people who saw images from the surveillance video on the news, Martin denied any involvement, despite police confronting him with the video.

According to a report from the arresting officer, Martin's heart rate was so elevated during the police interview, "You could see the pressure in his neck."

According to police, the camouflage jacket, the beanie, and .380 handgun pictured in the video were recovered at Martin's house, about 1 1/2 miles from the Circle K. Ammunition found at Martin's house also matched shell casings at the scene, police say.

Court documents indicate police are still doing forensic testing but had enough evidence to arrest Martin on Monday.

"On April 20, 2015 at 7:45 a.m., detectives detained Seth Martin at his place of employment without incident in connection with this case," Phoenix Police Sergeant Trent Crump says in a statement.